flexible coupling means for separable shafts



Feb.V 24, 1959 A. w. sEYFRn-:D Re. '24,607

' FLEXIBLE couPLING MEANS FOR SEPARABLE sHAFTs '1m/Ewan. Arthur W. Seyfried BY @mi )n ATTORNEY 4 original Filed oct. 16. 1952 Feb. 24,- 1959 FLEXIBLE COUPLING MEANS FORl SEPARABLE SHAFTS :s sheets-Sheet 2 r ri BY )7W ATTORNEY' A. w. sEYFRlED Re. 24,607 I Feb- 24 1959 A. w. SEYFRIED Re. 247,607

` FLEXIBLE COUPLING MEANS FOR SEPARABLE SHAFTS Original Filed Oct. 16, 1952 5 Sheets-Sheet l,'5

INVENTOR. Arthur W. Seyfrisd United States Patent O FLEXIBLE COUPLING MEANS FOR SEPARAELE SHAFTS Arthur W. Seyfried, Racine, Wis., assignor to Scovill Manufacturing Company, Waterbury, Conn., a corporation of Connecticut Original No. 2,755,900, dated July 24, 1956, Serial No. 315,048, October 16, 1952. Application for reissue November 27, 1957, Serial No. 700,928

Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

This invention relates to ilexible coupling means and particularly to flexible coupling means for operatively connecting the armature and agitator shafts Vof motor driven disintegrating food mixers also known as blenders or liquidizers.

The essential parts of a disintegrating mixer of the kinddescribed herein comprise (1) a closed top, open bottom container for the food to be disintegrated or blended, (2) a closure member for said open bottom, which closure member preferably is integral with a shaft bearing in which is mounted an agitator shaft having an agitator on its upper end and a drive coupling member on its lower end, and (3) a power unit which consists of the motor, motor housing and a drive coupling member on the armature shaft adapted to coop. erate with the coupling member on the agitator shaft when the parts have been assembled in operative relationship. The power unit as a Whole serves as the base of the mixer and has means on its upper surface for supporting the container and closure member and centering them to facilitate engagement of the coupling members.

An important object of the invention is to provide flexible coupling means whereby self-finding driving engagement is established automatically between the respective coupling members on the armature and agitator shafts when the container, with its closure member and agitator unit, are positioned on the power unit base. The coupling herein shown and described avoids numerous objections inherent in prior art couplings which are metallic and non-llexible and require positive finding of the engaging positions of the rigid parts constituting the coupling, with resultant wear of the parts, and which when engaged create vibration transmitted through the coupling members to their respective shafts, bushings, bearings and other parts of the machine.

The vibration inherent in metallic drive couplings destroys the proper fitting of the agitator shaft in its bearing, resulting in leakage of the container contents and gumming of the shaft and its bushing. Comparative tests conducted by me showed the following results: A currently popular liquidizer, which employs a non-flexible metallic drive coupling between its armature and agitator shafts, showed leakage of the container contents (water) after less than four hours operation, whereas the mixer herein shown and described, equipped with my ilexible coupling members between the armature and agitator shafts, was operated for more than one hundred hours under water load without leakage of the container contents.

Perfect alignment of the drive and driven shafts is rarely attained in the placement of the container and its closure on the base. The resultant misalignment of the shafts may be lateral, axial or angular.y Such misalign- Re. 24,607 Reissued Feb. 24,l 1959 ice ment aggravates the vibration inherent in metallic couplings and, in the operation of the mixer, the effect may be likened to repeated hammer blows on the agitator shaft. This results in making the shaft bearing bellinouthed at top and bottom and pinching the shaft in its bushing between said distorted bearing ends. The misalignment also results in faulty engagement of the coupling members with resultant noise and undue wear `of the parts.

All these faults have been overcome by the use of the flexible coupling of my invention. This coupling enables me to use a long bearing in which the agitator shaft rotates without distortionof the bearing. K The couplingv automatically compensates for misalignment of the shafts, is quiet in operation and free from vibration.

-These desirable results are attained by vulcaniziug a plurality of specially formed teeth made of Vrubber to one face of a solid brass or brass-plated steel plate. Preferably the rubber teeth are formed integrally with each other, and are of automobile tire treadhardness. The teeth are shaped to provide maximum contact face area between pairs of cooperating teeth, and they resist distortion in operation as the result of centrifugal force. Each tooth is provided with a thickened base which provides the required support for the tooth as well as bulk of flexible material for a firm and durable connection between the teeth and plate. Details of construction of the coupling members will be understood from the drawing and following specification.

Although some examples of ilexible couplings may be found in the prior art, their construction and form are not suitable for eilcient operation in the transmission of rotary motion from separable drive to driven shafts.

Another advantage of my invention is the provision of a container rest on the upper surface of the power unit or base of the machine which eilciently supports the container and its closure and permits the container and closure to be placed in position speedily and easily.

Other objects and advantages will lappear from the following specication.

In the drawings:

Fig. 1 is a front elevational view, partly in vertical section, of a disintegrating food mixer embodying my invention. i

Fig. 2 is a plan view, on an enlarged scale, of one of the two tlexibledrive coupling members of the mixer.

flexible coupling members as they appear when the larmaj ture and agitator shafts are aligned.

Fig. 5 is a View similar to Fig. 4 but showing the same parts as they appear when said shafts are laterally misaligned.

Fig. 6 is a side elevational view showing the driveA coupling members as they appear when their respective shafts are misaligned axially, that is, angularly.

Fig. 7 is a view similar to Fig. 6, showing the same parts as viewed at degrees to the position shown in Fig. 6 with the shafts in the same misaligned positions.

Fig. 8 is a view similar to Fig. 6 showing the same parts as they appear from the side opposite that shown in Fig. 6.

Fig. 9 is a horizontal sectional view, on an enlarged scale, taken in the plane of the line 9-9 of Fig. 8, looking downwardly as indicated by the ',arrows.

Fig. l0 is a horizontal sectional view showing the container and container closure seated on the supporting means, the section being taken in the plane of the line 10-10 of Fig. l.

In the preferred embodiment of my invention shownin thev drawings, and referring particularly to Fig. 1, the mixer comprises a power' unitV which constitutes the base of the machine and includesa motor housing 11 having a flat top 12, enclosing the rnotor partly shown at 13. The armatureshaft 1'4fcarriesthe farr 15, andl a ilexible drive couplingmember 16, the latter being mounted externally of the housing 11 on the upper end of the armaturegshaft to rotateftherewith.

Onthe upper surface 12 of thepower unit housing 11 are four members which receive andsupport the combined container closure-and agitator unit. The four supporting members are spaced9() degrees apart, and each comprises a bracket 17 secured to the housing wall 12 by ascrew 18. On the` inner side of the bracket 17 is a container closure rest 19 vpreferably made of resilient materialsuch as rubber. Said closure rest 19 is retained by aninturned-upperportion 20 ony the bracketv 17, and at its bottom the rest isl extended inwardly radiallyv as indicated at 21 to-provide aseat for the container closure member indicated as' a whole at 22 and hereinafter described in detail.

The container 23 for holding the food to be disintegrated or blended may bea conventional jar, round in cross section, closed at one end and having a screwl threaded neck at-itsI opposite open end. I prefer to use a container having abodyy portion elliptical in cross section anda round, screw threaded neck 24 surrounding its bottom open end, adapted-for engagement withl the internally screw threadedportion 25 of the closure member 22.

The combined container closure and agitator unit 22 comprises said screw threaded portion 25, closure base 26 annular in form, integral with' the threaded portion 25, and oseton its inner circumferential edge to forma raised-concentric portion 27 whichmerges with the sleeve shaped bearing 28'rising from said concentric portion 27. Within the bearing-28 is a bushing 29 forfreception of the agitator shaft 30. TheV container closure member extends downwardly from the threaded portion 25 below the baserportion 26-and rests on the base extension 21 of the container rest 19 asindicated at 25. This arrangement provides a recess belowthe part 27 ofthe container closure for accommodating a drive couplingr member indicated as a whole at 31, mounted on the lower end of the agitator shaft 30, for separably meshing with the coupling member 16on the armature shaft.

The upper endof the agitator shaft is screw threaded at 32 and retained in thebearing. 28`by a hex nut 33. A pair of agitator blade members are mounted on the shaft 30 to rotate therewith. Preferably two downturnedblades 34 extend in opposite directions from an apertured ilat cross piece mounted'on the agitator shaft, and two upturned blades 35 similarly extend in opposite directions from-an apertured cross piece mountedon the agitator shaft at right angles to the rst mentioned blade memberand fixed on lthe shaft between the top of the bearing- 28 rand the nut 33.v These blades preferably extend at an angle of 40 to 45 degrees, and are non-tracking. The blades are flat, not pitched, and sharpened along their longitudinal edges, knife-like. The upturned blades operate within the elliptical portion of the container and the lower ends of the downturned blades terminate slightly above the threaded neck portion of the container. The

ends of the blades preferably are beveled, and thoughy container 23 andits closure member-22 are positioned "on the base 11 betweenthe four container rests 19, androtative movement of the container and its closure is resisted by vthe contour of the peripheral'surface`37 ofthe closure member. This surface 37 is provided with a series of curved depressions 38 separated by vertically extending ribs 39. When the containerv and its closure are positioned on the mixer base, between the container rests 19, the depressed surfaces 38 naturally are engaged by the inner faces of the-rests 19, and the vertical ribs 39 resist rotative movement of the container relatively to said rests.

The agitator blades rotate in the direction in which' the container is rotated relatively to its closure, and this tightens the closure on the container and prevents relative' movement in' the opposite direction between said" parts during the operation of the mixer.

Referring to Figs. 2 to 9, inclusive, illustrating the flexible coupling members indicated as a whole at 16 and 31v (Fig. l"), it will be understood that these members'are identical but one is mountedon the armature shaft with,- its teeth upwardly .directed and the other is mountedon:

the agitator shaft with its teeth directed downwardly, engaging each other whenv the parts are in operative position-asshownin Fig. 1.

One of the twol coupling members will be described' withy special reference to Figs. 2 and 3. It comprisesv a' brass plated steel or solid brass plate 40, centrally' apertured at 41 and screw threadedas indicated at 42. A plurality ofilexible1teeth43, preferably six in number, pro'- ject incircumfcrentially spaced relationship from one face of a disc 44 of the-same flexible material, preferably. ini

tegraltherewith. They preferred material from whichtheteetha and: discareformed is rubber of the hardness' of automobile -tire treads. The disc 44 is relatively. thin inthe circumferential region between the teeth 43 butzis thickf cned inl the centralI area 45'surrounding an openingwhich' registerswith'the plate openingf41. The flat` face of the resilient disc-*44 isivulcanized to the'metal plate 40 andi.

theresilient material of the disc also coats the circumferential edge of theplate 40. The toothed disc andi the plate when thus connected constitute an integral base and support for the flexible teeth 43.

Each tooth hasa contact face 46 which extends radially with respect to the axis of the -coupling member, and is.

flat-in ak vertical planeperpendicular to the disc 44,- from itsV root or junction with said `disc 44 to its free edge or tip, Opposite itsv contact face 46; said tooth has anfinclined'surface 47 which slopes from the'narrow flat tip 48 to thetooth root where it joins the disc 44 along-a lineV 49 parallel to the face 46. Thetooth 43, therefore, has substantial thickness between the contact face 46 and the opposite inclined surface 47 in the -base portion where it yjoins the disc 44. This thickness is evidentin the form of the outer beveled `circumferential face 50 which-joins saidlopposite surfaces 46 and 47 as well as the base ory disc 44 and the'tip surface 48fofA the tooth. The said cir'- cumferential-face 50 coincides with the periphery'oflthe disc 44 at the root of the tooth but is inclined inwardly towardits junction with the-tip surface 48. The inner side 51fof the tooth v43 mergeswith the central thickened portion 45sof-the` disc 44.

' The said thickened portiony 45is curved or cut away between the'teeth-asindicatedl at 52 fory the `purpose of accommodating thel teeth 431of-the cooperating coupling member when-therespectiveshafts onl which they areA mounted are not aligned.

While six teeth have beenshown-as the preferred con-1 struction ofl the-coupling .member 16 and 31, the number may bevaried.

Preferably the# coupling/members A16 vand 31--are mounted on theirl respective shafts by means of the, screw threads 4201-1v the metal portion of each of the coupling members, engagingscrew threads on said shafts 14. and 30.

A's shown' inEigs'.' 1 and' 4, when the armature shaft 14"and' a'gitatorfsh'aft'v 30 are in alignment, the teeth of` the coupling members 16 and 31 engage each other in such manner that the contact faces 46 of the teeth of one member have maximum contacting engagement with the faces 46 of the teeth of the other member, and corresponding parts of the said members register with each other circumferentially and annularly.

In Fig. 5, the said coupling members 16 and 31 are shown as they would appear in a sectional view taken in the plane of the line 4 4 of Fig. 1, but modified by assuming the shafts 14 and 30 to be laterally misaligned,V though parallel. In this position, part of the contact faces 46 of some of the teeth of one coupling member are not in contact with the contact faces 46 of cooperating teeth on the other, but extend into the space afforded by the cut away central portion 52 of the resilient disc 44, as indicated at 53 near the top of Fig. 5. Other of said teeth also are partly out of contacting engagement with teeth on the other coupling member to the extent'that they project circumferentially beyond the cooperating teeth as indicated at S4. In the rotation of the shafts and their coupling members the teeth successively occupy the positions indicated in Fig. 5, when the shafts are misaligned laterally.

Notwithstanding the misalignment described and the fact that the contact faces 46 of cooperating teeth do lnot register to as full an extent as they do when the shafts are perfectly aligned, efficient driving engagement is insured because of the form of the ample contacting faces and their capacity for adjusting themselves to the misalignment.

.When the shaft misalignment is axial, that is when the shafts 14 and 30 extend at an angle to each other, as shown in Figs. 6 to 9, inclusive, the contacting engagement of the faces 46 of the teeth 43 of the coupling members varies both radially and axially as the result of the divergent planes in which the respective coupling members are positioned relatively to each other. This isbest shown in Fig. 7 whereit is apparent that the distance indicated at 55 between the discs 44 at the right of the figure is greater than said distance at the opposite side. Therefore the faces 46 of some of the teeth of cooperating pairs of teeth are opposed by only a portion ofthe faces 46 of the cooperating teeth, and, due to the non-parallel relationship of the discs 44, only some of the faces 46 are in driving contact with each other. This is illustrated in Fig. 9, where two pairs of cooperating teeth are in nearly normal driving engagement as indicated at 56 and 57, while two pairs of cooperating teeth at the opposite side of the clutch have their faces 46 spaced apart and are out of driving engagement, as indicated at 58 and 59. The remaining pairs of cooperating teeth are also out of driving engagement although spaced apart to a lesser degree, as indicated at 60 and 61.

Fig. 9 illustrates an extreme condition of angular misalignment but even so, one or more pairs of the teeth of respective coupling members successively make driving contact between their faces 46 during the rotation of the shaft members, and provide efficient transmission of rotarymotion from the drive to the driven shaft with-l out wear and without noise and vibration. understood that when the coupling member 16 is rotated by the drive shaft 14, the teeth on said drive coupling automatically adjust themselves to make contact with the cooperating faces of teeth on the driven coupling member 31, and this is possible because of the exible qualities of the teeth. As explained in connection with Fig. 9, even when the shafts are misaligned to as v'great a degree as is possible in the placement of the container and its closure on the base, one or more pairs of cooperating teeth successively make driving contact and their faces 46 bear against each other in substantially parallel relationship so as to close the spaces indicated at 56 and 57. n

Mixers( of` the kind described are driven at 12,000

It Will lbe R. P. M. and at this speed the centrifugal forceis sum-1 cient to distort flexible teeth and to cause them to pro-- ject radiallyV beyond the circumference of the disc 44. I have avoided such action by making the teeth 43 of substantial thickness, and by sloping the wall 50 inwardly from the root of the teeth to their tips 48. This construction resists centrifugal force, and at no time do the teeth 43 extend beyond the circumference of the disc 44.

Changesvmay be made in details of construction and form of some of the parts without departing from the scope of my invention as set forth in Vthe appended claims.

Iclaim:

1. Flexible coupling means for drivingly connecting a pair of `separable shafts, comprising a coupling member fixed on each of said shafts, each of said coupling members comprising a rigid disc, a flexible disc having one of its faces securely joined to one face of the rigid disc and a plurality of exible teeth on the exposed face of said flexible disc, each of said teeth having a contact face perpendicular to the lsaid disc and extending radially with respect to the axis of the coupling member but spaced from the axial center of said member, the teeth of each disc being spaced apart circumferentially to receive between them the teeth on the other coupling member when said members 'are in driving relationship, the perpendicular contact faces of the teeth of one coupling member registering in maximum face area contact with the contact faces of the teeth of the other coupling member when said shafts are in alignment.

2. Flexible coupling means for drivingly connecting a pair of separable shafts, comprising a coupling member fixed on each of said shafts, each of said coupling members comprising a rigid support having a face at right angles to the axis'of its shaft, a plurality of llexible teeth on said support, each of said teeth having a contact face perpendicular to the face of the support and extending radially with respect to the axis of the coupling member but spaced from the axial center of said member, each tooth having a circumferential surface sloped inwardly from the periphery of the support to the tip of the tooth and an inclined surface opposite its perpendicular contact face, the teeth of each coupling member being spaced apart circumferentially to receive between them the teeth 0n the other coupling member, the said contact faces of each of said members facing each other when said coupling members are in driving relationship.

3. Flexible coupling means for drivingly connecting a pair of separableV shafts, comprising a coupling member xed on each of said shafts, each of said coupling members comprising a rigid support having a face at right angles to the axis of its shaft, a plurality of exible teeth on said support, each of said teeth having a contact face perpendicular to the face of the support and extending radially with respect to the axis of the coupling member but spaced from the axial center of said member, each tooth being of substantial thickness radially and circumferentially, and having a surface sloped inwardly from the periphery ofthe support to the tip of the tooth and an inclined surface opposite its perpendicular contact face, the teeth of each coupling member being spaced apart circumferentially to receive between them the teeth on the other coupling member, the said contact faces of each of said members facing each other when said Vcoupling members are in driving relationship, the contact faces of the teeth of one coupling member registering vin maximum face area contact with the contact faces vbers comprising a metal disc, a flexible disc having one of its faces securely joined to one face of the metal disc,

.andl a plurality of exible teeth integral with the flexible zee-sor' 1 7 disc' on" the exposed face' thereof, eachf' offsid'tee'th hai/'ingaaf c'ontactffac'e perpendicular to the'Ysaiddis'c-nd extend'- ing radially with respect to the axis of thenco'uplingmei ber but spaced from the axial' centerxof said member, each'tooth being of substantial thickness both radially' and circumferentially and having a circumferential surface sloped inwardly from the periphery of the disc to the tip of the tooth andan inclined surface opposite its contact face, the teeth of each member being spaced apartfcire circumferentially to receive betweenl them the teeth on the other coupling member whenv said members are" in driving relationship, the perpendicular contact faceso'ffthe teeth of one member registeringinmaximumface' area contact with the contactfaces of the teeth-of the other member when said shafts are in alignment;

5'. Flexible coupling` means for drivingly connecting' a'- pl'air of separable shafts, comprising a coupling member fixed on each of said shafts, cachot"l saidcouplirigniembers comprising. a metal disc, a rubber` disc having' one o f'f its facesvulcanized to one face" of the' metldisci; a'- thickened central portion and a plurality of 'exibleteeth integral with the rubber' disc onthe exposed facethereofy each of said teeth having a' contact face perpendicular tothe' said rubber disc andextending radiallywithrespecty to the axis of the coupling member between s'aid"thickenedl central portion and the periphery'of the rubb'er'disc, eachto'oth being of substantial thicknessboth radiallyl andl circumferentially and havingV a circumferential? surface sloped inwardly from the periphery'ofrthe dis'c'tothey tip'rv of thetooth and an inclined surfaceop'posite its4` contact face', the teethy of each member beingspaceclapart cir-- cumfere'ntially to receive between themy the teeth on the other coupling member when said'members are'idriv-A ing relationship, the perpendicular contact faces of the teeth of one member registeringfinraxmum'face area` contact with the contact faces of the teeth ofthe'other' member when said shafts are in alignment;

6; Flexible coupling means for drivingly connecting a pair of separable shafts each having screw threaded free ends, comprising a coupling member mounted on each of said shafts, each of said coupling'riiembe'rs comprising a metal disc centrally apertured and screw threadedfor engaging the threads on the shaft end, a exible discv having one of its faces securely joined to one face of" the metal dise, 'and a plurality of exible teeth integralwith the ilexible disc on the exposed' face thereof, each of said teeth having a contact face perpendicular tothe saiddisc end and extending radially with respect to the axis of the coupling memberl but spaced from theaxial center of said member, each tooth being of substantial thickness both radially and circumferentially and have a circumferential surface sloped inwardly from the periph` ery ofthe disc to the tip of the tooth and' an inclined surface opposite its contact face, the teeth ofeach member being spaced apart eircumferentiallyV toA receive bel tween them the teeth on the other coupling member vwhen said members are in driving relationship, the 'perpendicularicontact faces of the teeth of one member registering in maximum face area-contact with the contact faces of the teeth of the other member when sadshafts are in alignment.

7. Flexible coupling means fordrivinglyconnectinga pair of separable shafts, comprising a couplingy memberfixed on each of said shafts, each coupling'member comprsing a rigid disc, a resilient dise having one face securely joined to one face of the rigid disc, and a plurality of'v flexible teeth integral with the exposed face of said resilientv disc, said teeth having contact faces perpendicularV to said disc face, extending radially'but'spac'edv from -they arc longitudinally and laterally movable'relatively-to eachI other, coupling means for drivingly connecting said shafts including a flexible coupling member fixed on'one of said" shafts' comprising a rigid disc, aflexible dischavng--ort of'its faces `securely joined to one face of the rigid disc" and a plurality of flexible teeth on the exposed'faccofsaidj' flexible disc, each of said `teethv having a' Contact facer: perpendicular to the saiddisc and extending radially with" respect to the axis-of the coupling member but spaccitl from thc axial center ofsaid` member, the teeth" being spaced apart circumfcr'entially- I0. In combination with d pair of` separable? shafts1 which arev longitudinally' and laterally g movablev relatively* to each Other, coupling meansfor d'rivinglyl connecting: Saidsh'afts including allexible coupling member fixedL on one of said shafts comprising a rigid support having aijace"y at right angles to the axis of the shaftfa'nd aplurality 0)" flexible teeth on-said support, each of said vteeth hai/ing-v a contact'face perpendicular to thc facefof thcs'upport'andl eictending'radially with respect to the axisof the coupli: member but spaced from the axial center of said'me" cfr cach tooth havingV a circumferential surface slop'dl in.

wardly' from'th'e periphery of the supportto the'tip'of thc:-

tooth and'an inclined surface'opposite its perpendicularA contact face, the teeth being spaced apart circumferentially.

11; In combination with a pair of separable shafts` which are` longitudinally and laterally movable relatively1 to eachother, coupling means for drivingly connecting' said shafts including a fiexible'coupling member fixed Lori one of said shafts comprising a'rigid support having af face at right angles to'theaxis of the shaft, and'ap'lurality' of fiexibleteeth on said support, each of said 'teeth' having ct Contact face perpendicular to the' facev of the support-v' and extending radially with respect to theA axisvo'f'the'coupling memberl` but spa'c'cd from the axial cen'tev'r of said member, each tooth'beingof substantial 'thickness radially'- and circumfcrentially, and having'a' surface sloped-Timwardly from the periphery of the supp'ot'ttoy theftp' the tooth and an inclined surface opposite'itspe'r'p'endicu- -r lar Contact face, the teeth being spacedfapart circuncferentially.

12. In combination with' a pair of sparab'le shafts* rof its faces vulcanized to one face of thegrigiddiscj af" thickened `central portion surrounding said central` ap'er# ture and a plurality of flexible teethinteqgralwithithc rubber disc on the exposed face thereof; each offsaid teeth having: a` contact face perpendicular toth'e" said` rubber disc and extending' radially with respect to the; axis of the coupling member between said4 thickened?- central portonand the peripherylof therubber discjcacli tooth being of substantial thickness bothradiallyond cire" cumferentally and having a circumferential surface slopd inwardly from the periphery of the'disc toY thetip'fofth* tooth and an inclined "surface" opposite its'contac't :face:v

13. In combination with" ar pair of separable'4 shfts' which are'longitudinal'ly and laterally movoblfrlativcly to eachV other, at least one of which' has-a scrcwfthreade'di' free'. end, coupling means for drivingly c'o'nncctin'gf said shafts including a flexible coupling me'rnber mountdfo'ntured and screw threaded for engaging the threads on a shaft end, a flexible disc having one of itsV faces securely joined to one face of the rigid disc and a plurality of flexible teeth integral with the flexible disc on the exposed face thereof, each of said teeth having a contact face perpendicular to the said disc and extending radially with respect to the axis of the coupling member but spaced from the axial center of the member, each tooth being of substantial thickness radially and circumferentially and havinga circumferential surface sloped inwardly from the periphery of the disc to the tip of the tooth and an inclined surface opposite its contact face.

14. In combination with a. pair of separable shafts which are longitudinally and laterally movable relatively to each other, coupling means for drivingly connecting said shafts including a flexible coupling member fixed on one of said shafts comprising a rigid disc, a flexible disc having one of its faces securely joined to one face of the rigid disc and a plurality of flexible teeth on the exposed face of said flexible disc, each of said teeth having a contact face perpendicular to the said disc and extending radially with respect to the axis 0f the coupling member but spaced from the axial center of said member, the teeth being spaced apart circumferentially, and each tooth having an inclined surface opposite its perpendicular contact face, said inclined surface being joined to the flexible disc in a line parallel to the contact face, a circumferential face on each tooth which coincides with the periphery of the flexible disc at the tooth root, the flexible disc being thickened in the central portion and relatively thin between said teeth, the annular surface of each tooth merging with the thickened central portion of the flexible disc which is cut away circumferentially between the merged inner annular surfaces of thel teeth.

References Cited in the le of this patent or the original patent f UNITED STATES PATENTS 1,919,998 Blume July 25, 1933 2,083,037 Schmittgen June 8, 1937 2,109,501 Osius Mar. 1, 1938 2,278,125 Landgraf Mar. 31, 1942 2,309,347 Landgraf Jan. 26, 1943 2,512,407 Wood June 20, 1950 2,585,255 Kochner et al Feb. 12, 1952 2,700,443 Boice Ian. 25, 1955 2,742,127 Mumford et al Apr. 17, 1956 

